Linkage system



Oct. 28, 1958 1 JOHNSON 2,857,770

. LINKAGE SYSTEM Filed Sept. 17, 1956 y s Sheets-Sheet 1 FIG.

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LENARD H JOHNSON m mew ATTORNEYS Oct. 28, 1958 JOHNSON I 2,857,770

LINKAGE SYSTEM Filed Sept. 17, 1956 I 3 Sheets-Sheet 2 IN V EN TOR. LEN/4P0 H. JOHNSON A 7703/15 rs m mcew Oct. 28, 1958 Filed Sept. 17, 1956 L. H. JOHNSON LINKAGE SYSTEM 3 Sheets-Sheet 3 84 a7 26 as M IW "1 m; l ,8 I n, n I y 25 5a @451 22 24 NVENTOR.

I LEN/1RD H. JOHNSON ATTORNEYS i2,s57,770 Patented Oct. 28, 1958 LINKAGE SYSTEM Lenard H. Johnson, Pasadena, Calif, assignor to Consolidated Electrodynamics Corporation, Pasadena, Calif., a corporation of California Application September 17, 1956, Serial No. 610,292

3 Claims. (Cl. 74-21ll) This invention provides a linkage system for converting rectilinear motion of one body into rotary motion of another body.

This linkage system is particularly applicable to mechanisms requiring the rotation of a bar about a pivot by means ofsolenoid action. For example, it is often use ful tobe able to move the periphery of a rotatable driving wheel into and out of contact with the periphery of arotatable driven wheel. In the past, this was done by mounting the rotatable driving wheel on a bar secured by a pivot to a frame. The periphery of the driving wheel was arranged to be adjacent the periphery of the driven Wheel, and a solenoid plunger was rigidly connected to the bar at a point remote from the pivot. A solenoid coil was used to move the plunger and thereby carry the driving wheel into and out of contact with the driven wheel. The movement of the plunger in the solenoid was rectilinear, while the movement of the bar was rotary, the result being that any appreciable travel of the plunger caused it to bind in the solenoid.

This invention provides a linkage arrangement in which the. solenoid plunger is connected to the bar or link in such a manner that there is a lateral displacement of the link with respect to the plunger as the plunger follows its rectilinear path and the link follows its rotary path, thereby reducing the tendency for the plunger to bind in the solenoid.

Briefly, the invention contemplates a linkage comprising a frame and a block connected to the frame by a pivot. A stirrup having an opening is spaced from the block, and a link is attached at one end to the block and extends away from the pivot through the opening in the stirrup. A plunger is connected to the stirrup, and a solenoid is disposed around the plunger for moving the plunger and stirrup in a direction to rotate the link and block about the pivot. The plunger and stirrup move rectilinearly, and as the block and link follow a rotary path,-the link is free to slide longitudinally in the stirrup opening so that the plunger is not deflected from its rectilinear path in the solenoid.

In a preferred form of the invention, the stirrup is an actuator plate having an opening through it, and the link includes an elongated leaf spring at its outer end which is disposed through the opening in the actuator plate. A separate plunger is connected to the actuator plate on opposite sides of the link, and a separate solenoid is disposed around each plunger so that the link may be pulled from a neutral position in either of two directions. A rotatable driving wheel is mounted on the block and a separate rotatable driven wheel is disposed on opposite sides of the driving wheel so that when the link is moved in one direction by one of the solenoids, the driving wheel engages one of the driven wheels, and when the link is moved in the other direction by the solenoid, the drivingwheel engages the periphery of the other driven wheel.

These and other aspects of the invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: i

Fig. 1 is a side elevation, partially broken away, of the presently preferred embodiment of the invention;

Fig. 2 is a sectional elevation taken on line 2-2 of e- Fig. 3 is a fragmentary sectional view taken on line 33 of Fig. 1; and

Fig. 4 is a fragmentary sectional view, partially broken away, taken on line 44-of Fig. 1.

Referring to Figs. 1 and 2, a rotatable driving wheel it is supported by a pair of spaced roller bearings 12 mounted on a stationary shaft 14 having its inner end press-fitted into a bore 16 in a block 18 which is rotatably supported on a stationary shaft 2% parallel to shaft 14 and having its inner end press-fitted into a sleeve 22 formed integrally in the central portion and on the concave side of a dish-shaped frame 2d. A spacing ring 25 around the shaft 2t]: spaces the block from the frame, and a retaining ring 26 fitted into an annular groove 27 around the outer end of the shaft it) retains the block on the shaft 20.

A rubber friction band 23 is mounted on the peripheral portion of the driving wheel adjacent the frame, and a plurality of annular pulley grooves 321i are formed in the peripheral portion of the wheel remote from the frame. A plurality of O-ring belts 31 are disposed in the grooves and are connected to a driving motor (not shown), which supplies power to turn the driving wheel in a clockwise direction, as viewed in Fig. 1.

A first driven wheel 32 is secured by a key 33 to a rotatable power shaft 34 journalled on a pair of roller bearings 35 in each end of a bore 36 which extends through the upper (as viewed in Fig. 2) portion of the frame. The power shaft projects through the frame and its end remote from the first driven wheel is adapted to be connected to a load, e. g., a reel (not shown) for winding or unwinding a roll of magnetic tape. The first driven wheel lies in the same plane as the driving wheel, and has its periphery adjacent the friction band on the driving wheel.

A large pulley 38 having annular grooves 40 in its periphery is secured by a key 42 to the outer end of the power shaft adjacent the first driven wheel, and a nut 43 holds the pulley on the shaft.

A second rotatable driven wheel 45 is mounted on a pair of spaced roller bearings 4-6 supported on a statie-nary second driven wheel shaft 48 having its inner end press-fitted into a bore 5% in the lower (as viewed in Fig. 2) portion of the frame. A small pulley 52 is formed integrally on the outer end of the second driven wheel, and has a plurality of grooves 54 to receive a plurality of Q-ring belts 56 which connect the small pul ley to the large pulley. The second driven wheel lies in the same plane as the driving wheel, and has its periphery adjacent the lower portion of the periphery of the driving wheel at a point diametrically opposed to the point of adjacency of the driving wheel and the first driven wheel.

An elongated horizontal link in the form of a leaf spring 58 has its inner end (right end as viewed in Fig. 1) clamped to the under side of a notched portion 59 of the block by a bar clamp 60 secured with screws 61 to the block. The major surface of the leaf spring lies in a horizontal plane (as viewed in Pig. 1). The outer end of the leaf sprin extends through an elongated horizontal opening 62 in a vertical stirrup or actuator plate 64 which is perpendicular to the leaf spring. The central portion of the upper edge of the actuator plate is disposed in a downwardly opening slot 66 in a first vertieal plunger as disposed in an upper solenoid 70 having leads 71 to supply current to the solenoid. A horizontal pin 72 is press-fitted through a bore 74 in the upper plunger and extends through a hole I6 in the upper portion of the actuator plate to lock the plate to the upper plunger. The central portion of the lower edge of the actuator plate is similarly secured by a pin 77 to a lower vertical plunger '78 disposed in a lower solenoid 79, the lower plunger having an upwardly opening slot 80 to receive the lower edge of the plate. Current is supplied to the lower solenoid through leads 81. Each of the solenoids is secured to the frame by brackets 32 and screws 83.

The upper end of a tension spring 84 is secured by a hook 85 through a hole 86 (see Fig. 3) formed in an overhang $7 of the bar clamp 60. The lower end of the spring is secured by a hook 88 which passes through a hole 90 in the upper end of a vertical adjusting screw 91 which extends down through the outwardly extending portion of an L-shaped bracket 92 secured by a screw 93 to the frame. A separate hex nut 94 on each side of the outwardly extending portion of the L-shaped bracket permits the tension in the spring 84 to be adjusted to compensate for the pull produced on the driving wheel by the O-ring belts connecting the wheel to the motor. When neither solenoid is actuated, the compensating spring is set to hold the driving wheel in a neutral position, i. e., in the position shown in Figs. 1 and 2, so that the friction band is not in engagement with either of the driven wheels.

Each side edge of the actuator plate is turned in opposite directions so that each side edge is adjacent a respective edge of the leaf spring. This prevents the plunger from rotating about its longitudinal axis and avoids the possibility of the leaf spring becoming caught or cooked in the opening of the actuator plate.

The operation of the apparatus is as follows. To engage the driving wheel with the first driven wheel, the upper solenoid is energized to pull the upper plunger up into it. This carries the actuator plate and outer end of the leaf spring upwardly to rotate the block about its pivot in a clockwise direction (as viewed in Fig. 1). The leaf spring is flexible so that the upper plunger will bottom in its solenoid to obtain maximum pull and to avoid excessive heating of the solenoid coil. In this respect, the use of a flexible leaf spring is preferred to a rigid element because if the plunger were attached to an element which remained rigid as the driving wheel came into contact with the driven wheel, the solenoid would have to be very accurately located so the plunger I would bottom as the two wheels engaged with exactly the correct amount of force. In actual practice such an arrangement would require a very critical adjustment. This difliculty is avoided by using the leaf spring, which permits the plunger to bottom, and yet still exert enough force between the driving and driven wheels to avoid excessive slippage.

Thus, when the upper solenoid is actuated, the first driven wheel is in direct engagement with the driving wheel, and the power shaft is rotated at a relatively high rate of speed. To drive the reel at a lower speed, the upper solenoid is de-energized, and the lower solenoid is energized. This pulls the lower plunger down into its solenoid until it bottoms. The actuator plate and leaf spring rotate the block in a counterclockwise direction about its pivot, causing the driving wheel to engage the second driven wheel. The small pulley then drives the large pulley so that the power shaft is rotated at a reduced rate of speed.

To stop the reel, both solenoids are maintained in a de-energized condition, and the driving wheel automatically moves to the neutral positions shown in Figs. 1 and 2 due to the balance between the tension in the O-ring 4 belts on the driving wheel and the tension in the compensating spring.

Regardless of which direction the'block is rotated, the leaf spring slides longitudinally in the actuator plate opening so that neither plunger is deflected from its normal rectilinear motion, thus reducing the possibility of either plunger binding in its respective solenoid.

I claim:

. 1. A linkage system for converting rectilinear motion into rotary motion comprising a frame, a block connected to the frame by a pivot, an actuator plate spaced from block, the plate having an opening through it, a flexible leaf spring attached at one end to the block and extending away from the pivot and through the opening in the actuator plate to be slidable with respect to the plate, a plunger connected to the plate, and a solenoid disposed around the plunger for moving the plunger and plate in a direction to rotate the link and block about the pivot.

2. A linkage system for converting rectilinear motion into rotary motion comprising a frame, a block connected to the frame by a pivot, a rotatable wheel mounted on the block, a first movable body adjacent one peripheral portion of the wheel, a second movable body adjacent another peripheral portion of the wheel, an actuator plate spaced from the block, the plate having an opening through it, a link attached atone end to the block and extending away from the pivot and through the opening in the actuator plate, means for urging the actuator plate toward a neutral position to keep the rotatable wheel out of contact with either movable body, a first plunger connected to one edge of the plate, a second plunger connected to an opposite edge of the plate, a first solenoid disposed around the first plunger, means for energizing the first solenoid to move the first plunger and plate in one direction away from the neutral position to rotate the link and block about the pivot to cause the wheel to move toward and engage the first body, a second solenoid around the second plunger, and means for energizing the second solenoid to move the second plunger and plate in another direction to rotate the link and block about the pivot to cause the wheel to move toward and engage the second body.

3. A linkage system for converting rectilinear motion into rotary motion comprising a frame, a block connected to the frame by a pivot, a rotatable wheel mounted on the block, a first movable body adjacent one peripheral portion of the wheel, a second movable body adjacent another peripheral portion of the wheel, an endless belt type drive for the wheel which urges the block to rotate about the pivot in one direction, springing means urging the block to rotate about the pivot in the opposite direction, an actuator plate spaced from the block, the plate having an opening through it, a link attached at one end to the block and extending away from the pivot and through the opening in the actuator plate, a first plunger connected to one edge of the plate, a second plunger connected to an opposite edge of the plate, a first solenoid disposed around the first plunger, means for energizing the first solenoid to move the first plunger and plate in one direction to rotate the link and block about the pivot to cause the wheel to move toward and engage the first body, a second solenoid around the sec ond plunger, and means for energizing the second sole- References Cited in the file of this patent UNITED STATES PATENTS 2,694,110 Roberts Nov. 9, 1954 

